我想在ViewPager中添加3个底部点，像这样。
我使用FragmentActivity和支持库ViewPager。
当前回答
下面是我如何做到这一点，有点类似于上面的解决方案。只要确保在下载完所有图像后调用loadDots()方法即可。
private int dotsCount;
private TextView dotsTextView[];
private void setupAdapter() {
adapter = new SomeAdapter(getContext(), images);
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(0);
viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
}
private final ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}
@Override
public void onPageSelected(int position) {
for (int i = 0; i < dotsCount; i++)
dotsTextView[i].setTextColor(Color.GRAY);
dotsTextView[position].setTextColor(Color.WHITE);
}
@Override
public void onPageScrollStateChanged(int state) {}
};
protected void loadDots() {
dotsCount = adapter.getCount();
dotsTextView = new TextView[dotsCount];
for (int i = 0; i < dotsCount; i++) {
dotsTextView[i] = new TextView(getContext());
dotsTextView[i].setText(R.string.dot);
dotsTextView[i].setTextSize(45);
dotsTextView[i].setTypeface(null, Typeface.BOLD);
dotsTextView[i].setTextColor(android.graphics.Color.GRAY);
mDotsLayout.addView(dotsTextView[i]);
}
dotsTextView[0].setTextColor(Color.WHITE);
}
XML
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="match_parent"
android:layout_height="180dp"
android:background="#00000000"/>
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/introImageView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<LinearLayout
android:id="@+id/image_count"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00000000"
android:gravity="center|bottom"
android:orientation="horizontal"/>
</FrameLayout>
其他回答
下面是我如何做到这一点，有点类似于上面的解决方案。只要确保在下载完所有图像后调用loadDots()方法即可。
private int dotsCount;
private TextView dotsTextView[];
private void setupAdapter() {
adapter = new SomeAdapter(getContext(), images);
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(0);
viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
}
private final ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}
@Override
public void onPageSelected(int position) {
for (int i = 0; i < dotsCount; i++)
dotsTextView[i].setTextColor(Color.GRAY);
dotsTextView[position].setTextColor(Color.WHITE);
}
@Override
public void onPageScrollStateChanged(int state) {}
};
protected void loadDots() {
dotsCount = adapter.getCount();
dotsTextView = new TextView[dotsCount];
for (int i = 0; i < dotsCount; i++) {
dotsTextView[i] = new TextView(getContext());
dotsTextView[i].setText(R.string.dot);
dotsTextView[i].setTextSize(45);
dotsTextView[i].setTypeface(null, Typeface.BOLD);
dotsTextView[i].setTextColor(android.graphics.Color.GRAY);
mDotsLayout.addView(dotsTextView[i]);
}
dotsTextView[0].setTextColor(Color.WHITE);
}
XML
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="match_parent"
android:layout_height="180dp"
android:background="#00000000"/>
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/introImageView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<LinearLayout
android:id="@+id/image_count"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00000000"
android:gravity="center|bottom"
android:orientation="horizontal"/>
</FrameLayout>
viewPager.addOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
switch (position) {
case 0:
img_page1.setImageResource(R.drawable.dot_selected);
img_page2.setImageResource(R.drawable.dot);
img_page3.setImageResource(R.drawable.dot);
img_page4.setImageResource(R.drawable.dot);
break;
case 1:
img_page1.setImageResource(R.drawable.dot);
img_page2.setImageResource(R.drawable.dot_selected);
img_page3.setImageResource(R.drawable.dot);
img_page4.setImageResource(R.drawable.dot);
break;
case 2:
img_page1.setImageResource(R.drawable.dot);
img_page2.setImageResource(R.drawable.dot);
img_page3.setImageResource(R.drawable.dot_selected);
img_page4.setImageResource(R.drawable.dot);
break;
case 3:
img_page1.setImageResource(R.drawable.dot);
img_page2.setImageResource(R.drawable.dot);
img_page3.setImageResource(R.drawable.dot);
img_page4.setImageResource(R.drawable.dot_selected);
break;
default:
break;
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
我的手工解决方案:
在布局中:
<LinearLayout
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/dots"
/>
在活动中
private final static int NUM_PAGES = 5;
private ViewPager mViewPager;
private List<ImageView> dots;
@Override
protected void onCreate(Bundle savedInstanceState) {
// ...
addDots();
}
public void addDots() {
dots = new ArrayList<>();
LinearLayout dotsLayout = (LinearLayout)findViewById(R.id.dots);
for(int i = 0; i < NUM_PAGES; i++) {
ImageView dot = new ImageView(this);
dot.setImageDrawable(getResources().getDrawable(R.drawable.pager_dot_not_selected));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
dotsLayout.addView(dot, params);
dots.add(dot);
}
mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
selectDot(position);
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
public void selectDot(int idx) {
Resources res = getResources();
for(int i = 0; i < NUM_PAGES; i++) {
int drawableId = (i==idx)?(R.drawable.pager_dot_selected):(R.drawable.pager_dot_not_selected);
Drawable drawable = res.getDrawable(drawableId);
dots.get(i).setImageDrawable(drawable);
}
}
以下是我提出的解决方案。
由于我们只需要在视图分页器中显示一些图像，因此避免了使用片段的麻烦。 实现了视图页面指示器(底部的点没有任何额外的库或插件) 在视图页面指示器(圆点)的触摸上，页面导航也在发生。 请不要忘记在资源中添加您自己的图片。 请随意评论和改进它。
A)下面是我的activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="schneider.carouseladventure.MainActivity">
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/viewpager"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RelativeLayout
android:id="@+id/viewPagerIndicator"
android:layout_width="match_parent"
android:layout_height="55dp"
android:layout_alignParentBottom="true"
android:layout_marginTop="5dp"
android:gravity="center">
<LinearLayout
android:id="@+id/viewPagerCountDots"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerHorizontal="true"
android:gravity="center"
android:orientation="horizontal" />
</RelativeLayout>
</RelativeLayout>
B) pager_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/imageView" />
</LinearLayout>
C) MainActivity.java
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener, View.OnClickListener {
int[] mResources = {R.drawable.nature1, R.drawable.nature2, R.drawable.nature3, R.drawable.nature4,
R.drawable.nature5, R.drawable.nature6
};
ViewPager mViewPager;
private CustomPagerAdapter mAdapter;
private LinearLayout pager_indicator;
private int dotsCount;
private ImageView[] dots;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
pager_indicator = (LinearLayout) findViewById(R.id.viewPagerCountDots);
mAdapter = new CustomPagerAdapter(this, mResources);
mViewPager.setAdapter(mAdapter);
mViewPager.setCurrentItem(0);
mViewPager.setOnPageChangeListener(this);
setPageViewIndicator();
}
private void setPageViewIndicator() {
Log.d("###setPageViewIndicator", " : called");
dotsCount = mAdapter.getCount();
dots = new ImageView[dotsCount];
for (int i = 0; i < dotsCount; i++) {
dots[i] = new ImageView(this);
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
params.setMargins(4, 0, 4, 0);
final int presentPosition = i;
dots[presentPosition].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
mViewPager.setCurrentItem(presentPosition);
return true;
}
});
pager_indicator.addView(dots[i], params);
}
dots[0].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));
}
@Override
public void onClick(View v) {
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
Log.d("###onPageSelected, pos ", String.valueOf(position));
for (int i = 0; i < dotsCount; i++) {
dots[i].setImageDrawable(getResources().getDrawable(R.drawable.nonselecteditem_dot));
}
dots[position].setImageDrawable(getResources().getDrawable(R.drawable.selecteditem_dot));
if (position + 1 == dotsCount) {
} else {
}
}
@Override
public void onPageScrollStateChanged(int state) {
}
}
D) CustomPagerAdapter.java
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
public class CustomPagerAdapter extends PagerAdapter {
private Context mContext;
LayoutInflater mLayoutInflater;
private int[] mResources;
public CustomPagerAdapter(Context context, int[] resources) {
mContext = context;
mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mResources = resources;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
View itemView = mLayoutInflater.inflate(R.layout.pager_item,container,false);
ImageView imageView = (ImageView) itemView.findViewById(R.id.imageView);
imageView.setImageResource(mResources[position]);
/* LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(950, 950);
imageView.setLayoutParams(layoutParams);*/
container.addView(itemView);
return itemView;
}
@Override
public void destroyItem(ViewGroup collection, int position, Object view) {
collection.removeView((View) view);
}
@Override
public int getCount() {
return mResources.length;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
}
E) selecteditem_dot.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" android:useLevel="true"
android:dither="true">
<size android:height="12dip" android:width="12dip"/>
<solid android:color="#7e7e7e"/>
</shape>
F) nonselecteditem_dot.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval" android:useLevel="true"
android:dither="true">
<size android:height="12dip" android:width="12dip"/>
<solid android:color="#d3d3d3"/>
</shape>
如果有人想要构建一个带有缩略图作为指示器的viewPager，可以选择使用这个库: 用于viewPager的ThumbIndicator，也可以将图像链接作为资源。
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